Am I a bad person?

My moms birthday is tomorrow. I love her but don't enjoy spending a lot of time with the family (past family issues). She bought tickets to go whale watching two hours away. I don't want to spend four hours driving and however long on the boat. Shes upset but I told her I would take her to lunch/dinner. And I'm going to get her a gift. She got tickets without asking and my boyfriend can't take off work and I need to study, call job opportunities, and finish up other errands. I feel like a bad person.